Opioid Growth Factor (OGF) is a naturally occuring substance in the body that helps to keep normal growth of tissue under control. Researchers at the Hershey Medical Center have discovered that OGF inhibits growth of human pancreatic cancer and perhaps other cancers when it is transplanted to animals. In some studies, OGF has been administered to human subjects with cancer and AIDS and has been well tolerated. The purpose of this study is to determine the appropriate dose, route of administration, side effects and duration of effects after the administration of opioid growth factor.